The present invention concerns a wiper arm for an automobile.
More specifically, the invention concerns a wiper arm of the type comprising a body extending longitudinally from its rear driving end towards its front end which bears a wiper blade, and wherein, in cross-section, at least a section of the arm body has an upturned U-shaped cross-section defined by two wings mutually connected by an upper back and extending towards the surface to be wiped, consisting of a downstream wing remaining substantially perpendicular to the back and an inclined upstream wing forming an acute angle relative to a median plan parallel to the downstreamwing to form an aerodynamic deflector integrated in the wiper arm which the action of a relative downwind direction, tends to urge the wiper arm towards the surface to be wiped.
An example of such a wiper arm is described and represented in document DE-A-3.343.318 in which the wiper arm is created from one piece in serrated, bent sheet metal. In the front portion of the aerodynamic deflector, the upstream wing is globally inclined and curved with its concavity oriented towards the flux of air corresponding to the relative wind direction applied to the wiper arm while wiping the windshield, by taking into account the forward movement of the vehicle.
The goal of this invention is to propose a wiper arm of this type which is created in order to improve the performance and rigidity, and to simplify its fabrication.
With this goal in mind, the invention proposes a wiper arm of the type mentioned above, characterized by the upstream wing presents a substantially curved surface, and the value of the acute angle of the inclined upstream wing ranges between 30xc2x0 and 45xc2x0.
According to other characteristics of the invention:
the value of the inclined acute angle ranges between 32xc2x0 and 35xc2x0;
the height of the downstream wing is below the height of the upstream wing, and the ratio of the two heights ranges between 0.65 and 0.85;
in cross section the value of the angle between the straight line passing by the lower edges of the downstream and upstream wings and the tangent to the upper back at the level of the median plane ranges between 7xc2x0 and 16xc2x0;
at least one of the wings, notably the upstream wig, contains a longitudinal reinforcement rib;
at least one of the wings, notably the downstream wing, contains an interior reinforcement fold;
the acute inclined angle of the upstream wing varies progressively in a manner such that the two wings are parallel at the rear and front ends of the body of the wiper arm;
the wiper arm is created in one piece of serrated and bent sheet metal.